Create a custom function with the insert statement in SQLite3 in iOS

I am using SQLite3 in iOS and I would like to know if you can do this:

insert into MyTableUsers values ('test', md5('some_pass'))

In SQLite3, you can create a custom function for, for example, MD5. But only by using a select statement:

select md5('some_string') , it will return the result of the MD5 function by calling your MD5 implementation.

But how can I do that with just an Insert statement ?